fitting a data set to log-normal distribution function

Hi,
I have a data set of some velocity values. A very small number of these values are negative. The histogram of my data set looks skewed and very much like a log normal distribution. How can I fit my data to a lognormal distribution when there are negative values?! I would rather not just cut them out. Are there some probability distribution functions which look skewed but can account for negative values? The gamma distribution seems to be only for positive values too.
Thank you for your help.